1. Field of the Invention
The present invention relates to fiber optics, and more specifically, it relates to fiber pigtailing machines.
2. Description of Related Art
The new technologies of high-speed communications, computer networks, and high-precision gyroscopes use optoelectronic (OE) devices and fiber optics. The main disadvantage of these components is the small size of their light emitting and transmitting areas--only a few micrometers in diameter. This means that, for example, an optical fiber must be aligned with respect to a laser diode with sub-micrometer accuracies. This is a very difficult mechanical problem and is , for the most part, performed manually by highly-skilled technicians working with microscopes and high-precision manipulators. Stress and fatigue result in only a small number of these aligning and attaching (the, so called pigtailing process) operations performed per day and with large part-to-part variations in alignment tolerances. This low production rate results in high cost for the completed OE product. Some technologies exist to perform the sub-micrometer alignments automatically by maximizing the amount of light passing between the OE components; but these systems still rely upon an operator performing the alignment sufficiently well, say a few micrometers, that some level of light can pass between the components in the first place. Although very fast (sub-second) algorithms have been developed to maximize the coupling, one of the major drawbacks of active alignment is obtaining sufficient alignment to couple some light between the OE components in the first place.
Some systems use rigid mechanical fixturing to provide the initial alignment to pass some light between the OE components, but these systems are very massive, expensive, and are custom-designed for only a specific task; many OE manufacturers are small businesses and cannot afford the initial investment of such equipment. Laser welding techniques are very robust and provide sub-micron accuracies, but require a large initial investment for the laser welder. Other alignment techniques using robotics and batch processing show promise for lowering the cost of sub-micron alignment and attachment of fibers to OE devices. Passive alignment techniques using v-grooves and other features etched in silicon waferboards show promise for lowering the cost of fiber pigtailing and are compatible with array geometries; however, obtaining sub-micron accuracies using passive alignment has proven to be difficult.
A real need exists for low-cost, flexible, high-precision automated equipment which can perform many of the processes which are presently labor-intensive in manufacturing OE products. Because labor accounts for a significant fraction of pigtailing costs, a fully automated pigtailing station should be capable of operating unattended for significant periods of time. Such topics as parts handling and feeding, initiating the coupling of light and attachment to the OE device must be considered. Many OE companies are small and cannot afford a large initial investment for such a workstation, therefore low cost is essential. Finally, flexibility to pigtail different types of OE devices is desirable to greatly reduce the costs of retooling for different products.